Homologous organs indicate: MCQ with Answer and Explanation

Explanation:
BCG (Bacille Calmette-Guérin) is a live attenuated vaccine derived from Mycobacterium bovis, used to protect against tuberculosis, especially in children. DPT is for diphtheria, pertussis, tetanus; MMR for measles, mumps, rubella; OPV is oral polio vaccine. BCG is often administered at birth in endemic regions.

Explanation:
The liver is the body's largest internal organ, performing metabolism, detoxification, bile production, and protein synthesis. The gall bladder stores bile.

Explanation:
Collenchyma is a simple permanent tissue with living cells, unevenly thickened primary cell walls (cellulose and pectin), providing mechanical support and flexibility, especially in young stems and leaf petioles. Parenchyma is for storage and metabolism, sclerenchyma is dead, rigid with lignified walls, xylem conducts water.